Composite honing ring

ABSTRACT

The invention relates to a composite honing ring comprising a honing part and a carrier part, whereby both components are made of different materials and can contain plastic resins in particular. The invention is characterized in that the abrasive honing part ( 1 ) has a low porosity, especially less than 5%, and preferably contains fibrous reinforcing elements. The carrier part has higher elasticity than the honing part. Since the carrier part is elastic, it damps machine vibrations and bearing vibration received by said carrier part.

FIELD OF THE INVENTION

The present invention relates to composite honing rings consisting of anabrasive honing part (in the form of a gear tooth ring member) and aperipherally or internally arranged receiving ring, in the followingdesignated as the carrier part, on which the honing part is mountedwithout any transition element.

BACKGROUND OF THE INVENTION

Honing rings as well as their uses have long been known in the field ofgear tooth flank machining. They may be composed of different materials,the abrasive region mostly consisting of synthetic resin-bonded abrasivematerial, and the carrier rings being made of the same materials. Theabrasive part has considerable porosity, which, for some applications,is artificially induced or increased by adding hollow spheres or ceramicagglomerates.

This combinated system corresponds to the effect of conventionalgrinding wheels, while, on the one hand, vibrations are transmitted tothe work piece to be machined, and, on the other hand, the bore playcauses inaccuracies which must be corrected for before utilisation, soas to make a stable honing process possible. Irregularities of theabrasive part require reinforcements, for honing rings withoutreinforcement tend to be subject to uncontrollable tooth breakage, andare thus not secure in their operation.

SUMMARY OF THE INVENTION

The invention aims at avoiding the above drawbacks, which is achievedaccording to the invention by a composite honing ring of the above kind,characterized in that the abrasive honing ring part has low porosity, inparticular a porosity of less than 5%, and preferably contains fibrousreinforcing elements, and in that the carrier part has higher elasticitythan the honing part.

This low porosity is achieved, for example, by compressing the honingpart composition, e.g. by using hot-pressed epoxy resin. This reductionof porosity results in an increased strength, and it the same time theraggedness after indentation of the abrasive part is drasticallyreduced, which almost eliminates the tendency of chipping off the workpieces being honed and brings about high dimensional stability of thehoning ring.

The fibrous reinforcing elements preferably used in particular have alength of 0,5 to 10 mm. Advantageously, such fibers may be whiskers anddo not only reinforce the binder matrix, but in a further advantageousembodiment also participate in the machining of the work piece duringhoning—thus being abrasive—which results in additional smoothing of thework piece surface and thus an improvement of the surface quality.Whiskers are defined as fibrous single crystals of metals, oxides,borides, carbides, nitrides, polytitanate, carbon, etc., mostly ofpolygonal cross-section (see Römpp Chemie Lexikon, 9th edition, p. 5039,which is incorporated herein by reference).

The carrier part of the honing ring preferably consists of unfilledsynthetic resin, in particular epoxy resin, which is why the materialsof the abrasive honing ring part and the carrier part have differentdamping properties. The carrier part is elastic and causes damping ofmachine vibrations and bearing oscillations, which are absorbed by thecarrier part. Thus the invention is able to achieve optimum honingresults even in case of less stable machines and to prevent accumulatingprocess forces.

According to a further preferred embodiment of the invention, thecarrier part possesses flow properties under tension. When mounting theinventive part on a machine seat the carrier part encloses it withoutplay, i.e. similar to a press fit. This provides for a very high truthof running, even in case the tools are repeatedly exchanged, as such apress fit is maintained.

In a preferred embodiment the abrasive honing ring part of the compositehoning ring according to the invention is filled with abrasive grains,preferably consisting of corundum, SiC, metal nitrides, diamond and CBNgrain, in particular having a grain size of ≦200 μm, which makesefficient and uniform honing possible while at the same time keeping thewear of the honing ring low.

All the above properties taken together result in a good balance betweencosts and effectiveness, as in this way the honing ring has a muchlonger service life as compared to conventional honing rings. Servicelife is additionally prolonged by a reduction of the trueing cyclesnecessary, as well as by minimum adjustment values in the process oftrueing.

Composition of the Honing Ring Members

a) Reinforced honing part with indentation

Components:

Polishing grains, 50-95% by weight, preferably corundum having anaverage grain diameter of 200 μm or less; alternatively SiC, diamond,CBN, metal carbides, nitrides and microcrystalline corundum;

binder (resins), 5-50% by weight, preferably epoxy resins;

fillers, 0-15% by weight, inorganic metal salts and/or oxides, organicfillers;

fibrous materials, 1-10% by weight, preferably having a length of 0.5-10mm, made of glass, ceramics, carbon, plastics (e.g. aramides, amides,polyesters, etc.) and/or whiskers.

b) Carrier part

Components:

epoxide resins comprising different contents of curing agents, rangingfrom 0.02 to 0.3% by weight.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following the invention will be described in more detail by wayof examples with reference to the drawings.

FIG. 1 illustrates a honing ring having an internal indentation.

FIG. 2 shows a honing ring wherein an abrasive honing part is outwardlyarranged.

FIGS. 3 and 4 show corresponding cross-sections of honing rings.

FIG. 5 shows a machine seat on a carrier body of the honing ring,wherein the machine seat is not biased.

FIG. 6 shows a machine seat on the carrier body of the honing ring,wherein the machine is biased.

FIG. 1 illustrates a honing ring having an internal indentation; FIG. 2shows a honing ring wherein the abrasive honing part is outwardlyarranged. FIGS. 3 and 4 show corresponding cross-sections of honingrings. FIG. 5 outlines a machine seat, not yet biased, on the carrierbody of the honing ring. FIG. 6 shows the same arrangement as FIG. 5,the machine seat being biased here, though.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows a honing ring having an internal honing part 1 and thecarrier body 2 encircling it. Carrier body 2 consists of epoxy resinwhich preferably is not filled, showing flow properties under pressure.This feature makes it possible to mount the honing ring on the honingmachine seat in such a way that it is utilizable even after minortrueing and immediately shows optimum concentric running properties. Byreleasing the bias of the machine flange, the press fit is removed andthe honing ring may be withdrawn.

FIG. 1 also shows that honing part 1 is made of a grinding/polishingmass consisting of grinding grains 4, fibrous components 5 and resinousbinding agent 3 and optional fillers. The components mentioned arelisted under “composition of the honing ring members” and may be variedaccording to the type of material to be machined.

FIGS. 2, 3, and 4 show variants and sectional views of honing rings,respectively; the features described for FIG. 1 remain the same for allvariants, though.

FIG. 5 shows a honing ring having a metal machine seat 6, which isplaced on the honing ring without exerting pressure. In this case, thehoning ring bore, together with the flange bore form a cylindricalsurface, i.e. the honing ring and the flange bore are flush. Mountingthe honing ring on the seat (not shown) of the grinding machine drivecan be accomplished easily without jamming.

FIG. 6 shows the same honing ring as FIG. 5, the difference being thathere machine seat 6 has been biased. In this case, elastic carrier body2 is jolted, resulting in a slight reduction of the bore of the ringbody (indicated by reference numeral 7 in FIG. 6). This deformationbrings about the optimum fit of the honing ring on the seat,guaranteeing its superior running characteristics.

What is claimed is:
 1. A composite honing ring comprising a honing partand a carrier part, wherein the two components are made of differentmaterials and include synthetic resins, wherein the abrasive honing ringpart has a porosity of less than 5% and includes fibrous reinforcingelements, and wherein the carrier part has higher elasticity than thehoning part.
 2. A composite honing ring, comprising: an abrasive honingpart of a first material having a predetermined porosity and apredetermined elasticity; and a carrier part of a second material havingan elasticity that is higher than the predetermined elasticity of theabrasive honing part, wherein the first and second materials aredifferent and include synthetic resins.
 3. A composite honing ring,comprising: an abrasive honing part of a first material having aporosity of less than 5% and a predetermined elasticity; and a carrierpart of a second material having an elasticity that is higher than thepredetermined elasticity of the abrasive honing part, wherein the firstand second materials are different.
 4. A composite honing ring,comprising: an abrasive honing part of a first material includingfibrous reinforcing elements and having a predetermined porosity and apredetermined elasticity; and a carrier part of a second material havingan elasticity that is higher than the predetermined elasticity of theabrasive honing part, wherein the first and second materials aredifferent.
 5. The composite honing ring of claim 4, wherein thereinforcing elements have a length of 0.5 to 10 mm.
 6. The compositehoning ring of claim 4, wherein the reinforcing elements are whiskers.7. The composite honing ring of claim 4, wherein the reinforcingelements include abrasive material.
 8. A composite honing ring,comprising: an abrasive honing part of a first material having apredetermined porosity and a predetermined elasticity; and a carrierpart of a second material having an elasticity that is higher than thepredetermined elasticity of the abrasive honing part, wherein the firstand second materials are different and wherein the carrier partpossesses flow properties under tension.
 9. A composite honing ring,comprising: an abrasive honing part of a first material having apredetermined porosity and a predetermined elasticity; and a carrierpart of a second material having an elasticity that is higher than thepredetermined elasticity of the abrasive honing part, wherein the firstand second materials are different, and wherein the second materialincludes unfilled synthetic resin.
 10. The composite honing ring ofclaim 9, wherein the unfilled synthetic resin is epoxy resin.
 11. Acomposite honing ring, comprising: an abrasive honing part of a firstmaterial having a predetermined porosity and a predetermined elasticity,wherein the honing part is filled with abrasive grains selected from thegroup consisting of corundum, SiC, metal nitrides, diamond and CBNgrains; and a carrier part of a second material having an elasticitythat is higher than the predetermined elasticity of the abrasive honingpart, wherein the first and second materials are different.
 12. Thecomposite honing ring of claim 11, wherein the abrasive grains have agrain size of ≦200 μm.